Hi, I got a few questions that I need an explanation. please don't just copy-paste the definition from google give me a 4-5 sentence explanation, maybe throw some links for reference. Thanks

• What is the difference between class definition and no class definition found?
• What are using for code repository?
• What is the difference between git fetch and git pull?
• what is jenkin jobs? and how you create it
• What is version management? and how it is used?